im just wondering how i can tell which compression pistons i would need at what setup... for example if i am to go with the twincharge kit from hahn and wanted to build my internals, how would i know what piston to go with?

 

If you're going to go turbo or twincharge, I'd go lower compression (8:5:1), since you'll be able to up the boost so much with the turbo. If you're going to stay supercharged, I'd go with stock (9:5:1), or higher (10:0:1) since you're limited to the capabilities of the M62. Higher compressions will create more heat, and will be easier to have KR, but will make more power.

 

crossed over, go with a custom ordered 9.5:1 or the 8.5:1 compression that is available for a setup like you stated.

 

I have 10.5:1 diamond forged pistons and a 2.7 pulley boosting 17lbs of boost with no knock. The key is high freaken octane. In my case meth injection works perfect in preventing knock. However, this would not be safe if wan't for other mods that provide better cooling also. These pistons along with every other mod out there for our cars and a ported head I put down 318WHP. There is alot more power left in there but I haven't messed too much with the timing & i'm taking step by step witht the AFR to see where I start getting knock.

 

so if i go with an 8.5:1 compression piston what mods does that limit me to?
im new to this whole compression thin so please donr flame but does that mean i cant use meth injection then for example?

 

You should start a thread posting your complete mods, dyno numbers, info on your tune, etc. People would like to know this stuff. I know when I go to do engine work, I'll want to know what has worked for other people.

 

The moly side skirt coating and the top thermal barrier coating on the Diamon Pistons we sell allow you to raise compression while maintaing the same boost and KR levels you had before. The raise in heat due to compression is negated by the reduction of heat created from friction on the cyilnder walls and the heat retention of the tops of stock pistons.

 

I would like to know more about this setup too. It appears with your setup, I could own 330-350 to the wheels without a blower swap. That would be nice especially since you're only running a 2.7" pulley!

 

i will definately keep that in mind for this spring, with so many options available i dont want to get stuck in one direction...if i were to twincharge for example and then eventually run a straight single turbo i wouldnt want to have to do internal work twice to accomodate one specific setup. i dont know if that makes sense but i know if i have 350 hp eventually ill either want to up my bost/performance or just get rid of my car all together and get something else like the camaro.

 

Why is it that all the guys making all the power are not here!!!

 

Because we are busy working on the cars.

 

^^^^ your not one of them!!!!!!!!!






















JK, I kno some of ur plans.

 

haha yep...Got a GSX getting worked on in the garage now.

 

You should call and ask the vendor that made your kit what they suggest.

 

I dont know much about compression ratios. But would 8.5:1CR pistons decrease horsepower compared to the stock 9.5. I know the lower ratios pistons are neccesary fo high boost. But if you wre to put in lower compreesion ration pistons while still at low levels of boost would you lose hp?

 

what about if you were upgrading ur supercharger to the whipple & you already had several mods to ur car like mine such as:
GM Stage 2 w/ 2.8" pulley
CAI
3" downpipe w/ no cat
3" exhaust from downpipe back
Spec Stage 3 clutch &
Fidanza lightweight flywheel
What compression ratio do you guys think I should use & do you think diamond cut pistons are necessary & what is a good brand 4 them.

 

Yes you will lose power with lower comp. pistons at normal boost levels.

 

Do not use the Diamonds if you are going to twin charge. This will seriously limit your potential horsepower. 9:1 or lower is what gm even recommends. 10:1 for NA only applications. Go with 8:5:1 and rods if you plan on pushing the limits of your car. 10:5:1 I would personally only use with the stock supercharger. If your going for some mad power go lower do it right do it once.

 

Could we use the 10:1:1 diamond pistons if we do a blower swap?